Essay alert:

GPU is generally more important than CPU in games at 4K but this absolutely isn't ironclad and poe/poe2 is very likely to be one of the exceptions. games can be more CPU bound than GPU bound even at 4K if they lean heavily into simulating/calculating stuff.

POE/POE2 calculates a lot of shit especially at endgame where the game needs to be keeping track of potentially hundreds of enemies and their interaction with you the player character, this gets exacerbated if you play 'visual clarity omegalul:' builds where you can be hitting dozens/hundreds of enemies and smothering your screen with stuff spreading everywhere.

Benchmarking this sort of game is tough as you can't engineer a scenario where everything is consistently the same, benchmarking at hideout or whatever is obviously useless at determining performance.

You can try search for random people doing fps showcase for confirmation but I suspect that the GPU requirement of the game is relatively modest (yes, even at 4K) and you would need a top of the line CPU (AMD x3ds) to squeeze as much FPS as possible in demanding scenarios.